This recipe is special to me for one big reason. It isn't a complicated or fancy recipe, in fact it's as simple as it gets. It's not from my childhood and it wasn't passed down through my family. It's simply a biscuit that helped me launch my baking business. A couple years ago I had the idea of taking my career in baking to a different level and opening up shop. This is how I found myself down at London's Maltby Street Market come rain or shine, every weekend selling my wares. To my surprise the melting moments became one of the favourites (along with the salted peanut and chocolate cookie sandwich, filled with homemade marshmallow fluff). I think they remind us of being kids, they're a bit like shortbread and are simple and humble, almost British in style, when in fact this recipe hails from Australia. I may not run that business anymore, because I became too busy with other work (hello Patisserie Made Simple) but I still regularly whip up a batch of these biscuits. To add a little bit of sunshine to this disappointingly grey summer I have filled the biscuits with both vanilla buttercream and a bright passion fruit curd and let me tell you, one wont be enough!

To make the curd place the puree, yolks and sugar into a heatproof bowl and whisk together until combined. Place the bowl over a pan of simmering water and cook, stirring constantly until the mixture thickens. It should be thick enough to coat the back of a spoon. Take the bowl from the heat and add the butter, mixing together until melted and combined. Pour the curd into a sterilised jar and seal, refrigerating until needed.

Preheat the oven to 160C (140C fan) and line two baking trays with parchment paper. Place the butter, vanilla and icing sugar into a large bowl and beat together until smooth and creamy. Sift the remaining ingredients into the bowl and gently mix together until you form a uniform dough, this can easily be done either by hand with a wooden spoon or with a mixer.

Using your hands roll the dough into small balls (I weigh these, 20g each) and place onto the prepared trays leaving a couple of inches between each biscuit. Using a fork dipped in flour press the fork onto the centre of each biscuit leaving an indent.

Bake the biscuits in the preheated oven for 20-25 minutes or until uniformly coloured. These shouldn't brown around the edges (due to the slightly lower temperature) so if you want to confirm they are fully baked flip one over, there should be a uniform golden colour across the base. If there is a darker, almost damp looking patch in the middle pop them back in the oven for a few minutes.

Allow to cool on the baking trays for five minutes before transferring to a wire rack to cool completely. Whilst cooling make the buttercream. Place the butter into a large bowl and beat together until smooth and creamy, then slowly add in the icing sugar a little at a time, beating until fully combined. Once you have added all the sugar add the vanilla and salt and beat together until light and fluffy.

To assemble the biscuits place the buttercream into a piping bag fitted with a small plain piping tip a pipe a circle of buttercream around the edges of half the biscuits. Fill the hole left behind with some passion fruit curd and top with a second biscuit (if youre not making the curd you can also use the jam of your choice or even some salted caramel. These will keep well for around four days in a sealed container.